linux-stable.git/fs/proc, branch v6.12.2

fs/proc/kcore.c: fix coccinelle reported ERROR instances

2024-12-05T13:02:10+00:00

[ Upstream commit 82e33f249f1126cf3c5f39a31b850d485ac33bc3 ]

Coccinelle complains about the nested reuse of the pointer `iter' with
different pointer type:

./fs/proc/kcore.c:515:26-30: ERROR: invalid reference to the index variable of the iterator on line 499
./fs/proc/kcore.c:534:23-27: ERROR: invalid reference to the index variable of the iterator on line 499
./fs/proc/kcore.c:550:40-44: ERROR: invalid reference to the index variable of the iterator on line 499
./fs/proc/kcore.c:568:27-31: ERROR: invalid reference to the index variable of the iterator on line 499
./fs/proc/kcore.c:581:28-32: ERROR: invalid reference to the index variable of the iterator on line 499
./fs/proc/kcore.c:599:27-31: ERROR: invalid reference to the index variable of the iterator on line 499
./fs/proc/kcore.c:607:38-42: ERROR: invalid reference to the index variable of the iterator on line 499
./fs/proc/kcore.c:614:26-30: ERROR: invalid reference to the index variable of the iterator on line 499

Replacing `struct kcore_list *iter' with `struct kcore_list *tmp' doesn't change the
scope and the functionality is the same and coccinelle seems happy.

NOTE: There was an issue with using `struct kcore_list *pos' as the nested iterator.
      The build did not work!

[akpm@linux-foundation.org: s/tmp/pos/]
Link: https://lkml.kernel.org/r/20241029054651.86356-2-mtodorovac69@gmail.com
Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
Link: https://lkml.kernel.org/r/20220331223700.902556-1-jakobkoschel@gmail.com
Fixes: 04d168c6d42d ("fs/proc/kcore.c: remove check of list iterator against head past the loop body")
Signed-off-by: Jakob Koschel 
Signed-off-by: Mirsad Todorovac 
Cc: Mike Rapoport 
Cc: David Hildenbrand 
Cc: Oscar Salvador 
Cc: "Brian Johannesmeyer" 
Cc: Cristiano Giuffrida 
Cc: "Bos, H.J." 
Cc: Alexey Dobriyan 
Cc: Andrew Morton 
Cc: Yang Li 
Cc: Baoquan He 
Cc: Hari Bathini 
Cc: Yan Zhen 
Cc: Alexander Gordeev 
Signed-off-by: Andrew Morton 
Signed-off-by: Sasha Levin

Merge tag 'mm-hotfixes-stable-2024-11-16-15-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2024-11-17T00:00:38+00:00

Pull hotfixes from Andrew Morton:
 "10 hotfixes, 7 of which are cc:stable. All singletons, please see the
  changelogs for details"

* tag 'mm-hotfixes-stable-2024-11-16-15-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  mm: revert "mm: shmem: fix data-race in shmem_getattr()"
  ocfs2: uncache inode which has failed entering the group
  mm: fix NULL pointer dereference in alloc_pages_bulk_noprof
  mm, doc: update read_ahead_kb for MADV_HUGEPAGE
  fs/proc/task_mmu: prevent integer overflow in pagemap_scan_get_args()
  sched/task_stack: fix object_is_on_stack() for KASAN tagged pointers
  crash, powerpc: default to CRASH_DUMP=n on PPC_BOOK3S_32
  mm/mremap: fix address wraparound in move_page_tables()
  tools/mm: fix compile error
  mm, swap: fix allocation and scanning race with swapoff

fs/proc/task_mmu: prevent integer overflow in pagemap_scan_get_args()

2024-11-15T06:43:48+00:00

The "arg->vec_len" variable is a u64 that comes from the user at the start
of the function.  The "arg->vec_len * sizeof(struct page_region))"
multiplication can lead to integer wrapping.  Use size_mul() to avoid
that.

Also the size_add/mul() functions work on unsigned long so for 32bit
systems we need to ensure that "arg->vec_len" fits in an unsigned long.

Link: https://lkml.kernel.org/r/39d41335-dd4d-48ed-8a7f-402c57d8ea84@stanley.mountain
Fixes: 52526ca7fdb9 ("fs/proc/task_mmu: implement IOCTL to get and optionally clear info about PTEs")
Signed-off-by: Dan Carpenter 
Cc: Andrei Vagin 
Cc: Andrii Nakryiko 
Cc: Arnd Bergmann 
Cc: David Hildenbrand 
Cc: Matthew Wilcox 
Cc: Michał Mirosław 
Cc: Muhammad Usama Anjum 
Cc: Oscar Salvador 
Cc: Peter Xu 
Cc: Ryan Roberts 
Cc: 
Signed-off-by: Andrew Morton

Merge tag 'mm-hotfixes-stable-2024-11-09-22-40' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2024-11-10T17:04:27+00:00

Pull misc fixes from Andrew Morton:
 "20 hotfixes, 14 of which are cc:stable.

  Three affect DAMON. Lorenzo's five-patch series to address the
  mmap_region error handling is here also.

  Apart from that, various singletons"

* tag 'mm-hotfixes-stable-2024-11-09-22-40' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  mailmap: add entry for Thorsten Blum
  ocfs2: remove entry once instead of null-ptr-dereference in ocfs2_xa_remove()
  signal: restore the override_rlimit logic
  fs/proc: fix compile warning about variable 'vmcore_mmap_ops'
  ucounts: fix counter leak in inc_rlimit_get_ucounts()
  selftests: hugetlb_dio: check for initial conditions to skip in the start
  mm: fix docs for the kernel parameter ``thp_anon=``
  mm/damon/core: avoid overflow in damon_feed_loop_next_input()
  mm/damon/core: handle zero schemes apply interval
  mm/damon/core: handle zero {aggregation,ops_update} intervals
  mm/mlock: set the correct prev on failure
  objpool: fix to make percpu slot allocation more robust
  mm/page_alloc: keep track of free highatomic
  mm: resolve faulty mmap_region() error path behaviour
  mm: refactor arch_calc_vm_flag_bits() and arm64 MTE handling
  mm: refactor map_deny_write_exec()
  mm: unconditionally close VMAs on error
  mm: avoid unsafe VMA hook invocation when error arises on mmap hook
  mm/thp: fix deferred split unqueue naming and locking
  mm/thp: fix deferred split queue not partially_mapped

fs/proc: fix compile warning about variable 'vmcore_mmap_ops'

2024-11-07T22:14:59+00:00

When build with !CONFIG_MMU, the variable 'vmcore_mmap_ops'
is defined but not used:

>> fs/proc/vmcore.c:458:42: warning: unused variable 'vmcore_mmap_ops'
     458 | static const struct vm_operations_struct vmcore_mmap_ops = {

Fix this by only defining it when CONFIG_MMU is enabled.

Link: https://lkml.kernel.org/r/20241101034803.9298-1-xiqi2@huawei.com
Fixes: 9cb218131de1 ("vmcore: introduce remap_oldmem_pfn_range()")
Signed-off-by: Qi Xi 
Reported-by: kernel test robot 
Closes: https://lore.kernel.org/lkml/202410301936.GcE8yUos-lkp@intel.com/
Cc: Baoquan He 
Cc: Dave Young 
Cc: Michael Holzheu 
Cc: Vivek Goyal 
Cc: Wang ShaoBo 
Signed-off-by: Andrew Morton

proc/softirqs: replace seq_printf with seq_put_decimal_ull_width

2024-11-07T17:40:14+00:00

seq_printf is costy, on a system with n CPUs, reading /proc/softirqs
would yield 10*n decimal values, and the extra cost parsing format string
grows linearly with number of cpus. Replace seq_printf with
seq_put_decimal_ull_width have significant performance improvement.
On an 8CPUs system, reading /proc/softirqs show ~40% performance
gain with this patch.

Signed-off-by: David Wang <00107082@163.com>
Signed-off-by: Linus Torvalds

Merge tag 'vfs-6.12-rc5.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2024-10-21T17:48:24+00:00

Pull vfs fixes from Christian Brauner:
 "afs:
   - Fix a lock recursion in afs_wake_up_async_call() on ->notify_lock

 netfs:
   - Drop the references to a folio immediately after the folio has been
     extracted to prevent races with future I/O collection

   - Fix a documenation build error

   - Downgrade the i_rwsem for buffered writes to fix a cifs reported
     performance regression when switching to netfslib

  vfs:
   - Explicitly return -E2BIG from openat2() if the specified size is
     unexpectedly large. This aligns openat2() with other extensible
     struct based system calls

   - When copying a mount namespace ensure that we only try to remove
     the new copy from the mount namespace rbtree if it has already been
     added to it

  nilfs:
   - Clear the buffer delay flag when clearing the buffer state clags
     when a buffer head is discarded to prevent a kernel OOPs

  ocfs2:
   - Fix an unitialized value warning in ocfs2_setattr()

  proc:
   - Fix a kernel doc warning"

* tag 'vfs-6.12-rc5.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  proc: Fix W=1 build kernel-doc warning
  afs: Fix lock recursion
  fs: Fix uninitialized value issue in from_kuid and from_kgid
  fs: don't try and remove empty rbtree node
  netfs: Downgrade i_rwsem for a buffered write
  nilfs2: fix kernel bug due to missing clearing of buffer delay flag
  openat2: explicitly return -E2BIG for (usize > PAGE_SIZE)
  netfs: fix documentation build error
  netfs: In readahead, put the folio refs as soon extracted

proc: Fix W=1 build kernel-doc warning

2024-10-18T11:02:47+00:00

Building the kernel with W=1 generates the following warning:

  fs/proc/fd.c:81: warning: This comment starts with '/**',
                   but isn't a kernel-doc comment.

Use a normal comment for the helper function proc_fdinfo_permission().

Signed-off-by: Thorsten Blum 
Link: https://lore.kernel.org/r/20241018102705.92237-2-thorsten.blum@linux.dev
Signed-off-by: Christian Brauner

fs/proc: fix build with GCC 15 due to -Werror=unterminated-string-initialization

2024-10-17T07:28:07+00:00

show show_smap_vma_flags() has been a using misspelled initializer in
mnemonics[] - it needed to initialize 2 element array of char and it used
NUL-padded 2 character string literals (i.e.  3-element initializer).

This has been spotted by gcc-15[*]; prior to that gcc quietly dropped the
3rd eleemnt of initializers.  To fix this we are increasing the size of
mnemonics[] (from mnemonics[BITS_PER_LONG][2] to
mnemonics[BITS_PER_LONG][3]) to accomodate the NUL-padded string literals.

This also helps us in simplyfying the logic for printing of the flags as
instead of printing each character from the mnemonics[], we can just print
the mnemonics[] using seq_printf.

[*]: fs/proc/task_mmu.c:917:49: error: initializer-string for array of `char' is too long [-Werror=unterminate d-string-initialization]
  917 |                 [0 ... (BITS_PER_LONG-1)] = "??",
      |                                                 ^~~~
fs/proc/task_mmu.c:917:49: error: initializer-string for array of `char' is too long [-Werror=unterminate d-string-initialization]
fs/proc/task_mmu.c:917:49: error: initializer-string for array of `char' is too long [-Werror=unterminate d-string-initialization]
fs/proc/task_mmu.c:917:49: error: initializer-string for array of `char' is too long [-Werror=unterminate d-string-initialization]
fs/proc/task_mmu.c:917:49: error: initializer-string for array of `char' is too long [-Werror=unterminate d-string-initialization]
fs/proc/task_mmu.c:917:49: error: initializer-string for array of `char' is too long [-Werror=unterminate d-string-initialization]
...


Stephen pointed out:

: The C standard explicitly allows for a string initializer to be too long
: due to the NUL byte at the end ...  so this warning may be overzealous.

but let's make the warning go away anwyay.

Link: https://lkml.kernel.org/r/20241005063700.2241027-1-brahmajit.xyz@gmail.com
Link: https://lkml.kernel.org/r/20241003093040.47c08382@canb.auug.org.au
Signed-off-by: Brahmajit Das 
Cc: Cyrill Gorcunov 
Cc: David Hildenbrand 
Cc: Stephen Rothwell 
Signed-off-by: Andrew Morton

fs/proc/kcore.c: allow translation of physical memory addresses

2024-10-09T19:47:19+00:00

When /proc/kcore is read an attempt to read the first two pages results in
HW-specific page swap on s390 and another (so called prefix) pages are
accessed instead.  That leads to a wrong read.

Allow architecture-specific translation of memory addresses using
kc_xlate_dev_mem_ptr() and kc_unxlate_dev_mem_ptr() callbacks similarily
to /dev/mem xlate_dev_mem_ptr() and unxlate_dev_mem_ptr() callbacks.  That
way an architecture can deal with specific physical memory ranges.

Re-use the existing /dev/mem callback implementation on s390, which
handles the described prefix pages swapping correctly.

For other architectures the default callback is basically NOP.  It is
expected the condition (vaddr == __va(__pa(vaddr))) always holds true for
KCORE_RAM memory type.

Link: https://lkml.kernel.org/r/20240930122119.1651546-1-agordeev@linux.ibm.com
Signed-off-by: Alexander Gordeev 
Suggested-by: Heiko Carstens 
Cc: Vasily Gorbik 
Cc: 
Signed-off-by: Andrew Morton